Human (Prasuhn, 2019 #1475) (Prasuhn, 2020 #1476)
PME
후보: MPTP mouse, 젊은 PARKIN KO mouse 아니 neuronal loss 있는 쥐로 해야 하지 않나?
Cf) In contrast to mice, rats are relatively insensitive to MPTP. Thus, rats injected with doses of MPTP comparable to those in mice do not exhibit any significant dopaminergic neurodegeneration for unknown reasons.
31P-MRSI measures will most likely be the most sensitive marker to objectify alterations of mitochondrial bioenergetics in vivo.
Fig. 3. 31P-Magnetic resonance spectroscopy imaging for the assessment of in vivo mitochondrial bioenergetics. 31P-MRSI spectra of a representative subset of brain parenchyma will be taken using a double-tuned P-headcoil (Advanced Imaging Research, Cleveland, Ohio). To attain sufficient relaxation of the phosphorus metabolites, a repetition time of 4500 ms will be used together with a three-dimensional chemical shift imaging sequence (6 × 5 × 3 voxel, 6 kHz bandwidth, 1024 data points, 8:51 min measuring time).
The analysis procedures will follow an updated version of an already published protocol with an optimization of data acquisition. Peak positions and intensities will be calculated with the AMARES algorithm.
- We will examine ATP and (PCr), which reflects the overall high-energy phosphate turnover. PCr represents a high-energy reservoir linked to ATP in a bidirectional reaction in which ATP is formed by PCr and vice versa. In addition to PCr and ATP, the ratios of PCr/inorganic phosphate (Pi) and ATP/Pi will be evaluated as an indicator of intracellular energy status within the scope of this study.
A: 31P-MRSI spectrum. B: model fit on 31P-MRSI spectrum. C: background noise
- 가능
- Potential our plan: correlate CSF ATP - brain ATP - NAD+ 31P MRS
- QUESTIONS:
- PCr ATP
- 31P-MRSI has been used to measure the ratio of NAD+/NADH, which offers unique opportunities for recent niacin-based clinical trials in early PD REPAIR-PD: NCT03815916.
- ATPase activity?
PRS method shown: SNPs were taken from the study of Nalls et al. [6].
Cons
- Neuron-specific 아닌 듯
- Low spatial resolution Because of the extremely low concentrations of phosphate metabolites,
- Long acquisition time
- 뇌구조 구분 되나? 31P-MRS has a relatively poor spatial resolution (Prasuhn 2020)
[tentative plan]
In rodent (eg. MPTP-rat, gerbil), correlation between metabolite-31P MRS signal and other mitochondrial dysfunction marker (?) between normal vs MPTP rodents.
아니 neuronal loss 있어야 되나? 그럼 어떻게 neuronal loss 와 구분하나? 그래도 translation 위해선 neuronal loss 있는 쥐로 해야 하지 않나?
(Du, 2007 #1549) Protocol 수립, three-spin exchange model
The average integral ratios obtained from the fully relaxed 31P spectra in the absence of RF saturation were PCr/-ATP = 1.33 ± 0.14, _-ATP/Pi = 3.34 ± 0.56, and ATP/Pi total = 2.44 ± 0.38 (N = 16; Pitotal = Pi + Piex). If the ATP concentration in the human brain was assumed to be 3 mM (see Ref. 33 and references therein), other phosphate metabolite concentrations were calculated as [PCr] = 3.99 ± 0.42 mM, [Pi] = 0.90 ± 0.16 mM and [Pitotal] = 1.23 ± 0.20 mM (N = 16), respectively, based on the integral ratios (proportional to concentration ratios) that were experimentally measured in this work.
(Harper, 2016 #1201)
- MDD HUMAN patients: ATP (GW, WM), PCr, phosphocreatine, Pi (inorganic phosphate), and pH.
(Kondo, 2016 #1517)
MDD HUMAN patients: good protocol, 31P-MRS results are expressed as the ratio of the individual metabolite concentrations to the total phosphate signal acquired from the VOI. β-nucleoside triphosphate (β-NTP; largely ATP), PCr/Pi, ATP
{Iosifescu, 2008 #1553}
MDD Tx (Thyroid hormone) ↑ ATP, ↓ PCr (저자해석: atp level 을 일정하게 유지하기 위해 PCr 을 희생한 듯)
Baseline PCr was significantly higher in MDD subjects who responded to antidepressant treatment compared with nonresponders
Christen Klein clinical trials
| trial | cohort / dose | readout |
|---|---|---|
| P1 University of Minnesota | PD patients, 4w, before & after, UDCA (50 mg/kg/day) NCT02967250: OL, single group, n=20 | MRS 로 ATP 봄. |
| P2 University of Sheffield, The "UP" Study, PI: Oliver Bandmann | PD patients, 48w, 30, A Phase II, Placebo Controlled, DB, RCT To Assess The Safety And Tolerability Of 30 mg/kg Daily UDCA NCT03840005 | MDS-UPDRS 3, MRS ATP, PCr, Pi (centered on basal ganglia and related motor regions) |
| Univ of Sheffield, OL, single-arm, Univ of Minnesota? | 5 sPD patients, UDCA 6W, (week 1: 15 mg/kg/day; week 2: 30 mg/kg/day; and weeks 3-6: 50 mg/kg/day). 3 patients: The ATP concentrations in mM unit measured at pre/post-UDCA conditions are 2.68/2.73, 2.76/2.79, and 2.72/2.75 in subjects 1, 2 and 4, respectively. In the first 2 subjects, we also observed _10% and 48% reduction in the metabolic rate of ATPase reaction, which was accompanied by _5% and 8% increase of the metabolic rate of creatine kinase reaction in the same brains, respectively. |
(Hattingen et al. 2009, PMID)
19 PD (16 early & 13 advanced), 19 control, results: severity correlation? In the putamen and midbrain of both Parkinson’s disease groups, we found a bilateral reduction of high-energy phosphates such as ATP and phosphocreatine as final acceptors of energy from mitochondrial oxidative phosphorylation. In contrast, low-energy metabolites such as adenosine diphosphate and inorganic phosphate were within normal ranges.
Animal
{Naritomi, 1988 #1317}: gerbil brain, readout: ATP, phosphocreatine, In vivo 31P NMR spectroscopy permits the estimation of serial changes in Pi, PCr, ATP, and pHi in the same animals
{Crockard, 1987 #1316}: GERBIL Brain, readout: Pi, PCr, β-phosphate of ATP (?), ATP
{Bainbridge, 2014 #1118}: Piglet, ↑ Pi/epp, Both lowered Δ[oxCCO] and NTP/epp 1 h post-HI indicated mitochondrial impairment. Cf) (epp = exchangeable phosphate pool = Pi + PCr + 2γ-NTP + β-NTP). ATP contributes approximately 70% of the NTP signal e.g. in the rat pup (Mandel and Edel-Harth, 1966).
*Animals (piglets) dying before 48h had slower recovery of both Δ[oxCCO] and 31P ratios by 1 h after HI.
{Obrenovitch, 1988 #1202} (this is not imaging!): (fig3) baboon brain tissue concentration of (ie 31P MRS 는 안 함): ATP, PCr, Lactate, pH. Neutralized perchloric acid tissue extracts were analysed using spectrofluorometric enzymatic techniques (Lowry and Passonneau, 1972)
{Oláh, 2008 #1594} (this is not imaging!): HD TG mice brain, measured ATP (biochemical method, p4752, 결더니 역시 3 mM 나오네), not PCr
Studies of 31P MRS — comparison table
| cohort | N | control | N | Region | Magnet | ATP | PCr | Pi | ADP | Em | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| {Eleff, 1990 #1582} {Montagna et al., 1992 #1583} {Barbiroli et al., 1993 #1588} | Mitochondrial encephalopathies | 5 / 28 | |||||||||
| {Montagna, 1992 #1583} | Even no abstract | ||||||||||
| {Hattingen et al. 2009 #1585} | PD (early and advanced mixed) | 19 | age-matched healthy controls | 19 | Rest, putamen and midbrain | 3T | ↓ (~25%) (due to 원료 ATP 부족 or ATP 만들려 CK가 많이 써서) | ↓ (10-20%) ↓ (19-20%) due to ↓ ATP & ↑ PCr | ↑ (9%) | ||
| {Hu, 2000 #1584} | PD (early and advanced mixed) | 10 | age-matched healthy controls | 10 | Frontal lobe / Occipital lobe | 1.5T | NA (just assumed 3 mM) | ↓ (38%) / ↓ (22%) | ↑ (20%) / ↑ (9%) | ↑ (20%) / ↑ (9%) | ↑ but 못 믿음 (ATP 를 Assume) |
| {Hattingen, 2009 #1585} | PD (early and advanced) | 19 | age-matched healthy controls | 19 | temporo-parietal cortex, occipital cortex and a central voxel incorporating basal ganglia and brainstem | 1.5T | ↓ (30%) CK가 많이 | ↑ (11%) | ↑ (24%) | ↑ (24%) | ↑ (52%) |
| {Montagna, 1993 #1585} | PD (early and advanced mixed) | 10 | age-matched healthy controls | 10 | ↑ (52%) | ||||||
| {Barbiroli, 1999 #1586} | The % of maximal rate of ATP biosynthesis was normal. | = | ↑ (52%) | ↑ (trend) (not reliable because calculated from assumed ATP) | ↑ (not reliable because calculated from assumed ATP) | ||||||
| {Rango, 2006 #1587} | PD (early and advanced) | 20 | age-matched healthy controls | Visual cortex | 1.5T | Largely reduced ATP+PCr during recovery phase (normal during rest and activation phase) | |||||
Bandmann, MD, PhD (UNIVERSITY OF Sheffield)
Questions
- Fibroblast
- Any Parkin-PD patients?
- P trial
Uncertain Spans
| location | transcription | uncertainty |
|---|---|---|
| ATP / NAD+ ratios | _-ATP = 1.33 ± 0.14, _-ATP/Pi = 3.34 ± 0.56 | The leading underscores in _-ATP are visible in the source as a ligature/symbol for α-/β-ATP; preserved as visible. |
| Hattingen row | ADP ↑ (20%) / ↑ (9%) | ADP fold-change values appear to map to two regions but the row alignment is partly obscured; reconstructed by adjacency. |
| Christen Klein P1 row | 5 sPD patients 5-row dose escalation block | The 5-subject single-arm UDCA cohort overlaps with the P2 Sheffield UP Study; the visible rendering preserves the as-is sub-cell text. |
| Fig 3 caption | A / B / C panel labels | Panel labels are visible at the top of the embedded figure and in the status bar; preserved as visible. |